Primary hydatid cyst in the adductor magnus muscle.

Human hydatid cyst is a zoonotic disease caused by the larvae of the Echinococcus species, most commonly the Echinococcus granulosus. Although hydatid cyst can cause disease almost anywhere in the human body, it most commonly affects the liver and lungs. Primary musculoskeletal hydatid involvement is a very rare occurrence even in endemic regions. Musculoskeletal hydatid disease shows no pathognomonic clinical signs and symptoms. And the contribution of serology to the diagnosis is negligible due to the high rate of false-negative results. Therefore, radiological imaging studies have a critical role in the diagnosis of the disease. To the best of our knowledge, there are only a few case reports of primary hydatid involvement of the adductor magnus muscle in the current literature. Here we present a 55-year-old female patient with primary hydatid cyst in the adductor magnus muscle and discuss the case in terms of imaging.

Primary gluteal subcutaneous hydatid cyst.

Hydatid disease is a parasitic zoonosis caused by Echinococcus granulosus larvae. While it can affect almost any part of the human body, liver and lung are the two organs where the disease is most frequently detected. Subcutaneous hydatid cyst, which mostly develops secondary to iatrogenic spillage of cyst contents into incision area during a visceral hydatid cyst surgery, accounts for only 1.5 % of all cases of hydatid cyst. With only a limited number of reported cases, primary involvement of subcutaneous tissue by hydatid cyst is a much more rare occurrence as compared with the secondary form. Subcutaneous hydatid cysts tend to involve trunk and limb roots, and mostly present as a slowly-growing, painless, mobile mass with a normal overlying skin. To our knowledge, only a few cases of primary subcutaneous hydatid cyst in the gluteal region have been reported to date. Here, we present a 72-year-old farmer who presented with a painless lump in the gluteal region and diagnosed as having primary subcutaneous hydatid cyst.

Intravascular papillary endothelial hyperplasia: histomorphological and immunohistochemical features.

BACKGROUND: Intravascular papillary endothelial hyperplasia (IPEH) is a benign intravascular process with features mimicking other benign and malignant vascular proliferations. IPEH lesions predominate in the head-neck region and the extremities. The characteristic histomorphological feature of IPEH is a papillary structure covered with hyperplastic endothelial cells within the vascular lumen. It is critical that this clinically benign lesion should not be mistaken for well-differentiated vascular tumors. In addition to the characteristic histological features, other useful diagnostic features included the intra-luminal location of the lesion, an intimate association with the organizing thrombus, the absence of necrosis, cellular pleomorphism, and mitotic activity. In addition, immunohistochemistry may indicate the vascular origin and proliferative index. In this study, we evaluated histomorphological and immunohistochemical findings (CD31, CD34, FVIII, type IV collagen, SMA, MSA, CD105, and Ki-67 staining) of ten IPEH cases. METHODS: Ten IPEH cases were re-examined for a panel of histomorphological and immunohistochemical features. CD31, CD34, FVIII, Type IV collagen, SMA and MSA antibodies utilized for immunohistochemical analysis.The histomorphological and immunohistochemical findings were evaluated by two independent pathologists using light microscopy. RESULTS: All ten cases involved intraluminal lesions with characteristic features of IPEH. All ten cases (100%) were stained positive for CD31 and CD34. The degree of staining with FVIII, type IV collagen, SMA, and MSA was variable. CONCLUSION: In this series of specimens, CD31 and CD34 were the most sensitive markers indicating the vascular origin of the lesion. Staining for the other vascular markers (FVIII, type IV collagen, SMA and MSA) was variable. Different maturation degrees of lesions may account for the variation in immunohistochemical staining. Few previous investigations evaluated a wide range of antigen panels in IPEH sections. In our opinion, the evaluation of immune markers in a larger sample set will reveal new features in the maturity and developmental pathogenesis of vascular lesions and angiogenesis. IPEH is a benign lesion, which must be differentiated from malignant tumors such as angiosarcoma and Kaposi's sarcoma. Improved definition of IPEH lesions using immunohistochemical markers may enhance the ability to differentiate between various vascular lesions. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1381849312101856.

Development of six tumors in a sebaceus nevus of jadassohn: report of a case.

Nevus sebaceus of Jadassohn is a congenital cutaneous hamartoma comprised of multiple skin structures. It has the potential to develop into variety of neoplasms of various epidermal adnexal origins. While multiple tumors may occasionally arise, it is unusual for more than four tumors to arise simultaneously within a single sebaceus nevus. Here in, we report a case of a 70-year-old woman with six neoplastic proliferations including a syringocystadenoma papilliferum, pigmented trichoblastoma, tubular apocrine adenoma, sebaceoma, tumors of follicular infundibulum and superficial epithelioma with sebaceus differentiation arising in a long standing nevus sebaceus on the scalp. Our case is extraordinary because a single nevus sebaceus contained six neoplastic proliferations with differentiation toward the folliculosebaceous-apocrine unit.

Granulocytic sarcomas: difficulties in diagnosis.

Granulocytic sarcoma is an uncommon tumor composed of myeloid blasts and/or immature myeloid cells in an extramedullary site which is usually associated with acute or chronic myeloid leukemia. The tumor may also be the initial manifestation of leukemia. The histomorphological diagnosis of granulocytic sarcoma can be challenging to pathologists, especially in the absence of a known hematological disorder. In this case, differentiation of granulocytic sarcoma from malignant lymphomas and other small round cell tumors is very critical. Seven cases of granulocytic sarcoma are reported in this paper. One patient had granulocytic sarcomas at two different sites. Hematoxylin-eosin-stained sections were reexamined. Blastic, poorly differentiated, and well differentiated histopathological variants were found in two, five and one cases, respectively. Immunohistochemical studies were performed on formalin-fixed tissue from all cases using a avidin-biotin-peroxidase complex technique. The panel included antibodies against LCA, CD43, CD34, c-kit, myeloperoxidase, CD68 KP1, CD15, and CD99. All cases stained positively with LCA, CD43, CD34, myeloperoxidase, and CD68. Five cases were positive for c-kit, three cases were positive for CD15, and two cases were positive for CD99. An immunohistochemical panel including at least myeloperoxidase, CD68 and CD34 can be used for detection of myeloid differentiation. It is also important that granulocytic sarcoma be considered in the differential diagnosis of CD99-positive round cell tumors.